Light irradiating apparatus having light emitting diode used as light source

[54] LIGHT IRRADIATING APPARATUS

HAVING LIGHT EMITTING DIODE USED
AS LIGHT SOURCE

[75] Inventors: Yukio Ohmamyuda, Sagamihara;

Shigeru Kimura, Yokohama; Toru
Tanabe, Machida; Kazuhisa Iwasaki,
Yokohama; Takao Seto, Yokohama;
Hideki Kitamura, Yokohama;
Kazuhiko Sugimura, Yokohama;
Yasushi Senoo, Yokohama, all of
Japan

[73] Assignee: Stanley Electric Co., Ltd., Tokyo, Japan

[21] Appl. No.: 801,943

[22] Filed: Dec. 3, 1991

[30] Foreign Application Priority Data

Dec. 7, 1990 [JP] Japan 2-401774

Dec. 17, 1990 [JP] Japan 2-403505

Dec. 17, 1990 [JP] Japan 2-403506

Dec. 21, 1990 [JP] Japan 2-404101

Dec. 22, 1990 [JP] Japan 2-404364

[51] Int. Cl.-< F21V 5/04

[52] U.S. CI 362/235; 362/251;

362/252; 362/800

[58] Field of Search 362/32, 235, 251, 252,

362/800; 385/31, 33, 39, 115, 117, 119

[56] References Cited

U.S. PATENT DOCUMENTS

1.636,141 7/1927 Mammen 362/252

2,286.014 6/1942 Rowe 362/32

2.589,569 3/1952 Peter et al 362/32

3,437,803 4/1969 Ernst-Otto Seitz et al 385/117

3,513,306 5/1970 Le Vantine 362/235

3,825,336 7/1974 Reynolds 385/119

4,027,945 6/1977 Iverson 385/115

4.039,250 8/1977 Gaertner 385/31

4,185,888 1/1980 Quelle, Jr 385/115

4.272,156 6/1981 Ishibashi et al 385/117

4,355,863 10/1982 Aulich et al 385/39

4,380,791 4/1983 Nishizawa 362/32

4,403,273 9/1983 Nishioka 385/117

4,577,926 3/1986 Dewey et al 385/119

4,610,513 9/1986 Nishioka et al 385/119

4,699,452 10/1987 Mollenauer et al 385/39

4,729,076 3/1988 Masami et al 362/235

4,746,185 5/1988 Shahidi-Hamedani 385/39

4,770,482 9/1988 Sweeney et al 385/115

4,865,417 9/1989 Naohiro et al 385/31

4,914,747 4/1990 Nino 362/61

5,036,248 7/1991 McEwan et al 362/800

FOREIGN PATENT DOCUMENTS

0165181 6/1989 Japan 385/39

OTHER PUBLICATIONS

Hecht, "Optics", 1974, pp. 100-105, Addison-Wesley Pub. Co.

Primary Examiner—Albert J. Makay

Assistant Examiner—Alan B. Cariaso

Attorney, Agent, or Firm—Frishauf, Holtz, Goodman &

Woodward

[57] ABSTRACT

A light source is constituted by a plurality of light emitting units which are arranged opposite to a light irradiating lens such that light emission from a part of the light source is changed to light emission from the whole surface of the light source and vice versa. In addition, a light irradiating apparatus having a light emitting diode used therefor as a light source comprises optical fiber(s) arranged between the light emitting diode and a light emitting lens such that a light emitted from the light emitting diode can be conducted to the light irradiating lens is disclosed. One end of each optical fiber is located at the position in the vicinity of the light emitting diode and other end of the same is located at the position substantially coincident with the focus of the light irradiating lens. In another embodiment, an optical fiber employable for an optical radar system has an outlet end of the optical fiber which is formed by two inclined surfaces in a wedge-shaped configuration. An inlet end of the optical fiber is formed at a right angle relative to an optical axis of the optical fiber.